Dual-microphone camera

ABSTRACT

A camera is configured with multiple microphones to reduce wind noise in audio data collected by the camera. The camera receives motion data, which may comprise data indicating acceleration of the camera, a plurality of video frames received by the camera, or a background level of noise associated with one or more microphones configured on the camera. The camera determines a motion vector from the motion data. The motion vector is parallel to the direction of motion of the camera. The camera selects a subset of one or more microphones in the direction of the motion vector. By recording audio data using the one or more selected microphones, the camera reduces wind noise in the audio data.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/275,696, filed May 12, 2014, now U.S. patent No. ______, which isincorporated by reference in its entirety.

BACKGROUND

Technical Field

This disclosure relates to a camera system, and more specifically, tocontrolling multiple microphones during camera operation.

Description of the Related Art

Digital cameras are increasingly used in outdoors and sportsenvironments, particularly while a user, a user's equipment, or a user'svehicle is in motion. Such use can result in increased wind noisecaptured by a microphone. Wind noise is generally proportional to cameraspeed or wind speed, and can increase or decrease based on theorientation of the camera relative to the wind direction. Wind noise isdetrimental to video playback, as it obscures or otherwise interfereswith the audio portion of the captured video. Accordingly, the reductionof wind noise can improve the quality of captured video and improve acamera user's overall experience.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The disclosed embodiments have other advantages and features which willbe more readily apparent from the following detailed description of theinvention and the appended claims, when taken in conjunction with theaccompanying drawings, in which:

FIG. 1a illustrates a perspective view of a camera system, according toone embodiment.

Fig. 1b illustrates another alternative perspective view of a camerasystem, according to one embodiment.

Fig. 1c illustrates a perspective view of a rear of the camera system,according to one embodiment.

FIG. 2a illustrates a first perspective view of a front of a camera foruse with the camera system, according to one embodiment.

FIG. 2b illustrates a second perspective view of a front of a camera foruse with the camera system, according to one embodiment.

FIG. 2c illustrates a perspective view of a rear of a camera for usewith the camera system, according to one embodiment.

FIG. 3 is a block diagram illustrating electronic components of a camera300, according to one embodiment.

FIG. 4 is a flowchart illustrating a method for selecting a microphoneon a dual-microphone camera, according to one embodiment.

FIG. 5 illustrates a set of vectors used to select a microphone on adual-microphone camera, according to one embodiment.

DETAILED DESCRIPTION

The figures and the following description relate to preferredembodiments by way of illustration only. It should be noted that fromthe following discussion, alternative embodiments of the structures andmethods disclosed herein will be readily recognized as viablealternatives that may be employed without departing from the principlesof what is claimed.

Reference will now be made in detail to several embodiments, examples ofwhich are illustrated in the accompanying figures. It is noted thatwherever practicable similar or like reference numbers may be used inthe figures and may indicate similar or like functionality. The figuresdepict embodiments of the disclosed system (or method) for purposes ofillustration only. One skilled in the art will readily recognize fromthe following description that alternative embodiments of the structuresand methods illustrated herein may be employed without departing fromthe principles described herein.

EXAMPLE CAMERA SYSTEM CONFIGURATION

A camera system includes a camera and a camera housing structured to atleast partially enclose the camera. The camera comprises a camera bodyhaving a camera lens structured on a front surface of the camera body,various indicators on the front of the surface of the camera body (suchas LEDs, displays, and the like), various input mechanisms (such asbuttons, switches, and touch-screen mechanisms), and electronics (e.g.,imaging electronics, power electronics, etc.) internal to the camerabody for capturing images via the camera lens and/or performing otherfunctions. The camera housing includes a lens window structured on thefront surface of the camera housing and configured to substantiallyalign with the camera lens, and one or more indicator windows structuredon the front surface of the camera housing and configured tosubstantially align with the camera indicators.

FIGS. 1a and 1b illustrate various views of a camera system according toone example embodiment. The camera system includes, among othercomponents, a camera housing 100. In one embodiment, a first housingportion 102 includes a front face with four sides (i.e., a top side,bottom side, left side, and right side) structured to form a cavity thatreceives a camera (e.g. a still camera or video camera). In otherembodiments, the camera housing 100 may not include one or more sides orfaces. For instance, the camera housing 100 may not include a front orback face, allowing the front face and rear face of the camera to beexposed when partially enclosed by the top side, bottom side, left side,and right side of the camera housing 100.

In one embodiment, the camera housing 100 has a small form factor (e.g.,a height of approximately 4 to 6 centimeters, a width of approximately 5to 7 centimeters, and a depth of approximately 1 to 4 centimeters), andis lightweight (e.g., approximately 50 to 150 grams). The camera housing100 can be rigid (or substantially rigid) (e.g., plastic, metal,fiberglass, etc.) or pliable (or substantially pliable) (e.g., leather,vinyl, neoprene, etc.). In one embodiment, the camera housing 100 may beappropriately configured for use in various elements. For example, thecamera housing 100 may comprise a waterproof enclosure that protects acamera from water when used, for example, while surfing or scuba diving.

Portions of the camera housing 100 may include exposed areas to allow auser to manipulate buttons on the camera that are associated with thecamera functionality. Alternatively, such areas may be covered with apliable material to allow the user to manipulate the buttons through thecamera housing 100. For example, in one embodiment the top face of thecamera housing 100 includes an outer shutter button 112 structured sothat a shutter button 112 of the camera is substantially aligned withthe outer shutter button 112 when the camera is secured within thecamera housing 100. The shutter button 112 of the camera isoperationally coupled to the outer shutter button 112 so that pressingthe outer shutter button 112 allows the user to operate the camerashutter button.

In one embodiment, the front face of the camera housing 100 includes alens window 104 structured so that a lens of the camera is substantiallyaligned with the lens windows 104 when the camera is secured within thecamera housing 100. The lens window 104 can be adapted for use with aconventional lens, a wide angle lens, a flat lens, or any otherspecialized camera lens. In this embodiment, the lens window 104comprises a waterproof seal so as to maintain the waterproof aspect ofthe housing 100.

In one embodiment, the camera housing 100 includes one or moremicrophone ports 133. The microphone ports 133 are structured tosubstantially align with one or more microphones configured on thecamera when the camera is secured within the camera housing 100. Themicrophone port 133 provides a path for sound to travel from the outsideof the camera housing 100 to a microphone on the camera. In oneembodiment, the microphone port 133 is an opening that exposes themicrophone to the outside environment. In one embodiment, the microphoneport 133 features a waterproof cover that protects the microphone fromwater or dust. While the microphone ports 133 are located on the sidesof the camera housing 100 in the illustrated embodiment, the microphoneports 133 can alternatively be located on any surface of the camerahousing 100 to substantially align with the microphones, such as thefront and the back of the camera housing (for instance, in embodimentsin which the microphones are located on the front and back of thecamera),In one embodiment, the camera housing 100 includes one or moresecuring structures 120 for securing the camera housing 100 to one of avariety of mounting devices. For example, FIG. 1a illustrates the camerahousing secured to a clip-style mount 122. In this example, the camerahousing 100 includes a first plurality of protrusions (protrusions 124as shown in FIG. 1b ), and the mount 122 includes a second plurality ofprotrusions. Each protrusion includes a hole (hole 126 as shown in FIG.1b ) at a similar location within the protrusion such that the first andsecond pluralities of protrusions can interlock in such a way that theprotrusion holes substantially align. Continuing with this example, aturnable handscrew is inserted through the aligned holes, coupling thecamera housing 100 to the mount 122 such that the camera housing canpivotally rotate relative to the mount when the turnable handscrew is ina first unlocked position, and such that the camera housing is fixed inposition relative to the mount when the turnable handscrew is in asecond locked position. In other embodiments, the camera housing 100 canbe secured to a different type of mounting structure, and can be securedto a mounting structure via a different type of coupling mechanism.

In one embodiment, the camera housing 100 includes an indicator window106 structured so that one or more camera indicators are substantiallyaligned with the indicator window 106 when the camera is secured withinthe camera housing 100. The indicator window 106 can be any shape orsize, and can be made of the same material as the remainder of thecamera housing 100, or can be made of any other material, for instance atransparent or translucent material and/or a non-reflective material.

The described housing 100 may also be adapted for a wider range ofdevices of varying shapes, sizes and dimensions besides cameras. Forexample, an expansion module may be attached to housing 100 to addexpanded features to electronic devices such as cell phones, musicplayers, personal digital assistants (“PDAs”), global positioning system(“GPS”) units, or other portable electronic devices.

FIG. 1c is a rear perspective view of camera housing 100 illustrating asecond housing portion 128, according to one example embodiment. Thesecond housing portion 128 detachably couples with the first housingportion 102 opposite the front face of the first housing portion 102.The first housing portion 102 and second housing portion 128 arecollectively structured to enclose a camera within the cavity when thesecond housing portion 128 is secured to the first housing portion 102in a closed position.

In one embodiment, the second housing portion 128 comprises a door 130that allows the camera to be removed from the housing 100. The door 130pivots around a hinge 136 that allows the door 130 to be opened or shut.In one embodiment, a first fastening structure 138 located on the topface of the camera housing 100 detachably couples to a second fasteningstructure 140 on the door 130. The fastening structures 138, 140 securethe door 130 to the first portion 102 of the camera housing 100 in aclosed position when coupled, as illustrated in FIG. 1b . In oneembodiment, the fastening structure 138 comprises a hook-shaped lateralbar and the fastening structure 140 comprises an L-shaped bar. Thefastening structure 138 can pivot upwards to allow the door 130 to closeand can then be pressed down around the fastening structure 140 to holdthe door 130 in the closed position. In different embodiments, fasteningstructures for securing the door 130 can include, for example, a buttonassembly, a buckle assembly, a clip assembly, a hook and loop assembly,a magnet assembly, a ball and catch assembly, and an adhesive assembly,or any other type of securing mechanism.

In one alternative embodiment, the hinge 136 is instead located on thetop face of the housing 100 and the fastening structures 138, 140 areinstead located on the bottom face of the housing 100. Alternatively,the hinge 136 and fastening structures 138, 140 may be located onopposite side faces of the camera housing 100.

In one embodiment, the housing 100 includes a watertight seal so thatthe housing 100 is waterproof when the door 130 is shut. For example, inone embodiment, the door 130 includes a sealing structure positioned oninterior edges of the door 130. The sealing structure provides awatertight seal between the first portion of the camera housing 102 andthe door 130 when the first securing structure 138 on the top face ofthe camera housing 100 is coupled to the second securing structure 140on the top edge of the door 130.

In one embodiment, an outer hinge structure 132 on the bottom edge ofthe second housing portion 128 detachably couples to an inner hingestructure 134 on the bottom edge of the first housing portion 102 toform the hinge 136. For example, in one embodiment, the outer hingestructure 132 comprises one or more hook-shaped protrusions structuredto securely fasten to a rod-shaped member of the inner hinge structure134. Other mechanisms for coupling the second housing portion 128 to thehousing 100 may also be used in various alternative embodiments. Inother embodiments, the second housing portion 128 may be permanentlyattached to the first housing portion 102.

FIG. 2a illustrates a first perspective view of a front of a camera 200for use with the camera system, according to one embodiment. FIG. 2billustrates a second perspective view of a front of a camera for usewith the camera system, according to one embodiment. The camera 200 isconfigured to capture images and video, and to store captured images andvideo for subsequent display or playback. The camera 200 is adapted tofit within a camera housing, such as the housing 100 discussed above orany other suitable housing. As illustrated, the camera 200 includes alens 202 configured to receive light incident upon the lens and todirect received light onto an image sensor 312 internal to the lens. Thelens 202 is enclosed by a lens ring 204.

The camera 200 can include various indicators, including the LED lights206 and the LED display 208 shown in FIG. 2a . When the camera 200 isenclosed within the housing 100, the LED display 208 is configured tosubstantially align with the indicator window 106, and the LED lights206 are configured to be visible through the housing 100. The camera 200can also include buttons 210 configured to allow a user of the camera tointeract with the camera, to turn the camera on, and to otherwiseconfigure the operating mode of the camera. The buttons 210 may beembodied as a keypad, knobs, dials, individual buttons, switches, or anyother conventional user interface.

The camera 200 can also include a first microphone 212 a and a secondmicrophone 212 b, each configured to receive and record audio signals(“capture audio” hereinafter) in conjunction with recording video. Inthe illustrated embodiment, the camera 200 includes two microphones 212,but other embodiments of the camera 200 may include additionalmicrophones 212, located on any side/surface of the camera 200. In someembodiments, the first microphone 212 a and the second microphone 212 bare located on opposite surfaces of the camera 200 (e.g., front-back,left-right, top-bottom, etc.). Locating microphones 212 on oppositesurfaces of the camera 200 can ensure that at least one of the two (ormore) microphones 212 is always in a favorable location for minimal windnoise. For example, by locating microphones 212 on opposite surfaces ofthe camera 200, at least one microphone will always be on a camerasurface generally facing the direction of motion. The camera surfacefacing the direction of motion is in a low turbulence region andexperiences minimal turbulent pressure fluctuations. Microphones 212that experience minimal turbulent pressure fluctuations can be subjectto less wind noise than microphones 212 that experience more substantialturbulent pressure fluctuations.

The microphones 212 can be configured to capture audio simultaneously.Alternatively, a first microphone can capture audio while a secondmicrophone does not capture audio (for instance, in embodiments wherethe second microphone is exposed to an above-threshold amount of windnoise). The microphone configured to capture audio can switch based on achange in wind noise, wind direction, camera orientation, or the like).A side of the camera 200 includes an I/O port interface 214. Though theembodiment of FIG. 2a illustrates the I/O port interface 214 enclosed bya protective door, the I/O port interface can include any type or numberof I/O ports or mechanisms, such as USB ports, HDMI ports, memory cardslots, and the like. A side of the camera 200 also includes a memorycard slot 215, configured to receive a removable memory card on whichcaptured images and video can be stored.

FIG. 2c illustrates a perspective view of a rear of a camera 200 for usewith the camera system, according to one embodiment. The camera 200includes a door 216 that covers a removable battery and batteryinterface. The door 216 can be removed via the door release mechanism218. The camera also includes an expansion pack interface 220 configuredto receive a removable expansion pack, such as a display module, anextra battery module, a wireless module, and the like. Removableexpansion packs, when coupled to the camera 200, provide additionalfunctionality to the camera via the expansion pack interface 220.

Example Camera Configuration

FIG. 3 is a block diagram illustrating electronic components of a camera200, according to one embodiment. The camera 200 includes one or moremicrocontrollers 302 (such as a processor) that control the operationand functionality of the camera 200. A lens and focus controller 302 isconfigured to control the operation and figuration of the camera lens202. A system memory 304 is configured to store executable computerinstructions that, when executed by the microcontroller 302, perform thecamera functionalities described herein. A synchronization interface 306is configured to synchronize the camera 200 with other cameras or withother external devices, such as a remote control, a second camera 200,or a smartphone.

A controller hub 308 transmits and receives information from user I/Ocomponents. In one embodiment, the controller hub 308 interfaces withthe LED lights 206, the display 208, and the buttons 210. However, thecontroller hub 308 can interface with any conventional user I/Ocomponent or components. For example, the controller hub 308 may sendinformation to other user I/O components, such as a speaker.

A sensor controller 310 receives image or video input from the imagesensor 312. The sensor controller 310 receives audio inputs from one ormore microphones, such as microphone 212 a and microphone 212 b. Thesensor controller 310 may receive audio input from one microphone 212 ata time or may receive audio input from multiple microphones 212simultaneously. Furthermore, the sensor controller 310 can select one ormore of the microphones 212 from which the camera 200 receives andrecords audio inputs. Microphones 212 selected by the controller 310 forreceiving and recording audio are referred to herein as “activemicrophones.” Additional sensors, such as an accelerometer 314, may beconnected to the sensor controller 310. The accelerometer 314 collectsmotion data, comprising velocity and/or acceleration vectorsrepresentative of motion of the camera 200. The accelerometer 314 mayadditionally include a gyroscope to provide additional motion datarepresentative of the motion of the camera 200. The accelerometer 314 isrigidly coupled to the camera 200 such that any acceleration experiencedby the camera 200 is also experienced by the accelerometer 314.

Additional components connected to the microcontroller 302 include anI/O port interface 214 and an expansion pack interface 220. The I/O portinterface 214 may facilitate the camera 200 in receiving or transmittingvideo or audio information through an I/O port. Examples of I/O ports orinterfaces include USB ports, HDMI ports, Ethernet ports, audioports,and the like. Furthermore, embodiments of the I/O port interface 214 mayinclude wireless ports that can accommodate wireless connections.Examples of wireless ports include Bluetooth, Wireless USB, Near FieldCommunication (NFC), and the like. The expansion pack interface 220 isconfigured to interface with camera add-ons and removable expansionpacks, such as a display module, an extra battery module, a wirelessmodule, and the like.

Example Process for Using A Dual-Microphone Camera

FIG. 4 is a flowchart illustrating a method for selecting a microphoneon a dual-microphone camera, according to one embodiment. The method isperformed by the camera 200. For example, the camera 200 may include aprocessor 302 that executes instructions, stored on the system memory304, for performing the disclosed method. The method of FIG. 4 may beperformed before the camera 200 receives audio data or in real-time(while the camera 200 is receiving audio data). Additional oralternative steps may be included in other embodiments of the process ofFIG. 4.

The camera 200 receives 410 motion data from one or more camera sensors.The motion data includes information representative of the direction ofmovement of the camera 200. The motion data may also include informationregarding the magnitude of the camera's movement. In some embodiments,the motion data includes acceleration data. The acceleration dataindicates the acceleration of the camera 200 over a time interval. Thetime interval may begin when the camera 200 begins recording audio data,may begin before the camera 200 begins recording audio data, or maybegin as the camera 200 is recording audio data, for instance, inresponse to an above-threshold change in detected acceleration. In someembodiments, the motion data additionally or alternatively includesmotion estimation data. The motion data includes a plurality of videoframes collected by the camera 200 over a time interval, and includesdata describing motion of objects within the frames. In someembodiments, the motion data comprises audio data. The audio dataincludes a background noise level associated with each microphone 212.In some embodiments, the camera 200 receives 410 motion data while thecamera 200 is receiving audio or video data. Alternatively, the camera200 may receive 410 motion data even when the camera 200 is notreceiving audio or video data.

In one embodiment, the camera 200 receives 410 motion data from theaccelerometer 314 connected to the camera 200. The motion data from theaccelerometer 314 indicates the direction and magnitude of accelerationexperienced by the accelerometer 314, and thus the camera 200, over atime interval. In the context of this application, acceleration mayinclude translational acceleration, angular acceleration, and rotationalacceleration. The accelerometer 314 can measure acceleration in multipledimensions. The accelerometer 314 may also include one or moregyroscopes. The one or more gyroscopes enable the accelerometer 314 tomeasure angular acceleration and rotational acceleration.

In one embodiment, the camera 200 receives 410 motion data based on ananalysis of a plurality of video frames. In one example embodiment, theplurality of video frames can include video data received or captured bythe camera 200. Each frame in the plurality of video frames comprises aplurality of pixels at a particular image resolution. The plurality ofvideo frames may be associated with a frame rate. The frame rateindicates the time domain spacing between each image in the plurality ofvideo frames. Motion data describing motion of the camera 200 isdetermined by tracking the motion of objects represented by theplurality of video frames. For instance, an analysis that determinesthat an object in the video frames moves three meters to the left over atime interval can indicate that the camera 200 moves three meters to theright over the same time interval.

In a third embodiment, the camera 200 receives 410 motion data based onan analysis of audio data captured by the one or more microphones 212.The motion data can be determined based on the level of background noisereceived by one or more microphones 212 over a time interval. Forexample, the motion data may be background noise levels from eachmicrophone 212 configured on the camera 200. The motion vector may bedetermined from the motion data by determining the direction ororientation of the microphone 212 that picks up the least backgroundnoise.

The camera 200 determines 420 a motion vector based on the receivedmotion data. The motion vector is a vector in the direction of thecamera 200 movement. In other words, the motion vector points in thedirection of the camera's velocity. The magnitude of the motion vectorcan be equal to the speed of the camera 200, though in some embodimentsnot described further herein, the motion vector is merely a directionwithout a magnitude. In other embodiments, the motion vector may beequal to the speed of the camera but in the opposite direction of thecamera's velocity.

In embodiments in which the motion data comprises acceleration data, thecamera 200 determines 420 the motion vector by integrating theacceleration data. The motion data, comprising the direction andmagnitude of acceleration experienced by the camera 200, is integratedover time to determine the direction and magnitude of the camera'svelocity. The camera 200 may integrate the acceleration data inreal-time to dynamically determine 420 the camera's velocity from themotion data. The camera 200 determines 410 the motion vector from thecamera's velocity. The motion vector is equal in direction and magnitudeto the camera's determined velocity.

In embodiments in which the motion data is based on a plurality of videoframes, the camera 200 determines 420 the motion vector by determiningone or more pixel motion vectors. The pixel motion vector indicates thedisplacement of a region of pixels between two frames in the pluralityof video frames. For example, a pixel motion vector may indicate theposition of the region of pixels in a second frame as compared to theposition of the same region of pixels in a first frame. The camera 200determines the pixel motion vector by selecting a region of pixels. Theregion of pixels may comprise a single pixel, a macroblock of pixels, anoutline of an object, a region of similar pixels, an edge at which adiscontinuity in the frame occurs, or any other collection of pixels.The camera 200 determines the location of the region of pixels in thefirst frame. The camera 200 then determines the location of the sameregion of pixels in a second frame subsequent to the first frame in theplurality of video frames. The camera 200 may determine the location ofthe same region of pixels in the second frame using a conventional imageprocessing, machine vision, or image analysis algorithm that identifiesthe region of pixels in each frame. The camera 200 generates a pixelmotion vector that spans from the location of the region of pixels inthe first frame to the location of the same region of pixels in thesecond frame. The camera 200 may use a feature-matching algorithm, apixel-recursive algorithm, a stochastically-determined algorithm, anoptical flow algorithm, or any other computer or mathematical algorithmto determine the direction and magnitude of the distance between thedifferent locations of the region of pixels in the two video frames. Thepixel motion vector may be a 2-dimensional vector on the frame plane ora 3-dimensional vector that has a vector component normal to the frameplane.

The camera 200 determines 420 the motion vector for the camera 200 basedon the one or more determined pixel motion vectors and the frame rate ofthe plurality of video frames. The camera 200 can determine 420 themotion vector for the camera 200 based on the direction and magnitude ofthe one or more pixel motion vectors. For example, the pixel motionvector may indicate that the camera 200 has moved the distance of thepixel motion vector during the time interval between the two images.Thus, the motion vector is equal in direction and magnitude to the pixelmotion vector. In other embodiments, in which the motion vector isopposite the direction of the camera's motion, the motion vector may beequal in magnitude but opposite in direction to the pixel motion vector.

In embodiment in which the motion data is determined based on ananalysis of background noise received by one or more microphones 212over a time interval, the camera 200 determines 420 the motion vector bydetermining the level of background noise received by each microphone212 configured on the camera 200. In one example embodiment, the camera200 receives a level of background noise from each microphone 212. Thelevel of background noise may be received before or while the camerareceives video data. In one example embodiment, the lowest level ofbackground noise is the lowest decibel input into the microphone. Inanother example embodiment, the lowest level of background noise is thelowest sound intensity within a predetermined frequency range known tobe associated with background noise, such as wind noise, interference,or vibrational noise. The camera 200 determines which microphone 212 isassociated with the lowest background noise level. The camera 200determines 420 the motion vector based on the intensity of thebackground noise levels and the microphone 212 with the lowestbackground noise level. In one example embodiment, the camera 200determines that the motion vector is in the direction of the microphone212 with the lowest background noise level. The magnitude of the motionvector may correspond to or be proportional or inversely proportional tothe lowest background noise level. In other embodiments, in which themicrophone is opposite the direction of camera motion, the motion vectoris in the opposite direction of the microphone 212 with the lowestbackground noise level.

The camera 200 determines 430 an associated surface vector for eachcamera surface that includes a microphone 212. In one exampleembodiment, the surface vector is perpendicular to (or “normal to”) eachcamera surface that includes one or more microphones 212. In anotherexample embodiment, in which the camera surface and surface of themicrophone 212 are not parallel, the surface vector may be perpendicularto the surface of the microphone 212 included on the camera surface.

The camera 200 identifies 440 a subset of surface vectors. The angulardisplacement between each surface vector in the subset of identifiedsurface vectors and the motion vector is less than 90 degrees. Eachsurface vector with an angular displacement of less than 90 degrees fromthe motion vector (representative of a direction opposite the directionof motion of the camera 200) generally faces (at least in part) thedirection of the camera's movement. In another embodiment, the subset ofsurface vectors comprises only the surface vector associated with thesmallest angular displacement between the surface vector and the motionvector.

The camera 200 selects 450 one or more microphones 212 based on theidentified subset of surface vectors. For example, if the subset orsurface vectors include two surface vectors, each normal to a camerasurface including a microphone, one or both of the microphones 212 onthe surfaces normal to the subset of surface vectors are selected. Inone embodiment, the camera 200 only selects one microphone 212associated with the surface vector with the smallest angulardisplacement between the surface vector and the motion vector. Inanother embodiment, the camera selects each microphone 212 associatedwith a surface vector with an angular displacement of less than 90degrees between the surface vector and the motion vector. However, inother embodiments, the camera 200 selects 450 one or more microphones212 associated with the surface vector or vectors with the largestangular displacement between the surface vector and the motion vector.

The camera 200 records 460 audio data using the one or more selectedmicrophones 212. The camera 200 activates each selected microphone 212to record audio data. The camera 200 may record audio data using theselected microphones 212 while concurrently recording video data. Thecamera 200 can continue to record audio data using the selectedmicrophones 212 for a pre-determined period of time, until a userselects an input associated with stopping the recording of audio/video,or until an above-threshold change in the motion of the camera 200 isdetected. When an above-threshold change in the motion of the camera 200is detected, the camera 200 can select a different set of microphones212 from which to record audio data. In such a way, the camera 200 canchange active microphones 212 in real time based on changes in motion ofthe camera 200, allowing the camera 200 to record audio data only frommicrophones best positioned relative to motion of the camera(microphones likely to experience the least wind or static noise).

FIG. 5 illustrates a set of vectors used to select a microphone on adual-microphone camera 200, according to one embodiment. The vectorsinclude the motion vector 510 and surface vectors 520 and 530. FIG. 5also illustrates angular displacements θ_(A) 515 and θ_(B) 525. WhileFIG. 5 shows only two microphones 212 a and 212 b coupled to the camera200, any number of microphones 212 can be coupled to the camera 200.Furthermore, each of the any number of microphones 212 has an associatedsurface vector and angular displacement to the motion vector 510.

The illustrated camera 200 has four surfaces: surface A, surface B,surface C, and surface D. Surfaces A and C face the direction of bothwind and motion and thus experience lower levels of turbulent pressurefluctuations. Lower levels of turbulent pressure fluctuations (i.e., lowturbulence) occur at the leading edge of the camera 200, where air (orfluid) flow has not separated from the camera surface. Since turbulentpressure fluctuations result in wind noise, surfaces A and C arepreferable surfaces for a microphone 212.

The angular displacement θ_(A) 515 spans the surface vector N_(A) 520 tothe motion vector 510. The motion vector 510 is determined fromacceleration data, pixel motion vectors, wind noise levels, or any othersuitable motion data. In the illustrated embodiment, the motion vector510 is parallel to the direction of the camera's motion. Surface vectorN_(A) 520 is normal to the camera surface that includes microphone A 212a. In the illustrated embodiment, θ_(A) 515 is less than 90 degrees. Insome embodiments, the camera 200 will include the surface vector N_(A)520 in the selected subset of surface vectors since θ_(A) 515 is lessthan 90 degrees or because θ_(A) 515 is the smallest of all the angulardisplacements. Since the surface vector is included in the selectedsubset of surface vectors, the camera 200 can select the microphone A212 a for use to record audio data.

The angular displacement θ_(B) 525 spans the surface vector N_(B) 530 tothe motion vector 510. Surface vector N_(B) 530 is normal to the camerasurface that includes microphone B 212 b. In the illustrated embodiment,θ_(B) 525 is greater than 90 degrees. In some embodiments, since θ_(B)525 is greater than 90 degrees, or because θ_(B) 525 is larger than thesmaller angular displacement θ_(A) 515, the camera 200 will not includethe surface vector N_(B) 530 in the selected subset of surface vectorsand will thus not use microphone B 212 b to record audio data.

Additional Configuration Considerations

Throughout this specification, some embodiments have used the expression“coupled” along with its derivatives. The term “coupled” as used hereinis not necessarily limited to two or more elements being in directphysical or electrical contact. Rather, the term “coupled” may alsoencompass two or more elements are not in direct contact with eachother, but yet still co-operate or interact with each other, or arestructured to provide a thermal conduction path between the elements.

Likewise, as used herein, the terms “comprises,” “comprising,”“includes,” “including,” “has,” “having” or any other variation thereof,are intended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus.

In addition, use of the “a” or “an” are employed to describe elementsand components of the embodiments herein. This is done merely forconvenience and to give a general sense of the invention. Thisdescription should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

Finally, as used herein any reference to “one embodiment” or “anembodiment” means that a particular element, feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. The appearances of the phrase “in oneembodiment” in various places in the specification are not necessarilyall referring to the same embodiment.

Upon reading this disclosure, those of skill in the art will appreciatestill additional alternative structural and functional designs for acamera expansion module as disclosed from the principles herein. Thus,while particular embodiments and applications have been illustrated anddescribed, it is to be understood that the disclosed embodiments are notlimited to the precise construction and components disclosed herein.Various modifications, changes and variations, which will be apparent tothose skilled in the art, may be made in the arrangement, operation anddetails of the method and apparatus disclosed herein without departingfrom the spirit and scope defined in the appended claims.

What is claimed is:
 1. A method for activating at least one of aplurality of microphones configured within a camera, comprising;capturing, by each of the plurality of microphones, an audio signal;identifying one or more of the plurality of microphones based on thecaptured audio signals, each identified microphone associated with anaudio signal having an above-threshold amount of wind noise; determininga motion vector for the camera based on the identified microphones;selecting less than all of the plurality of microphones based on themotion vector, wherein each selected microphone is located on a camerasurface facing the direction of the motion vector; and capturing audiodata using only the selected microphones and not the unselectedmicrophones in the plurality of microphones such that the unselectedmicrophones do not produce audio signals.
 2. The method of claim 1,wherein the identified one or more microphones comprise microphones onadjacent surfaces of the camera.
 3. The method of claim 1, wherein themotion vector is determined such that one or more camera surfaces thatdo not include an identified microphone face the determined motionvector.
 4. The method of claim 1, further comprising: for each camerasurface including an identified microphone, determining a vector normalto the camera surface; and determining the motion vector based at leastin part on a combination of the determined normal vectors.
 5. The methodof claim 1, wherein selecting less than all of the plurality ofmicrophones comprises: for each camera surface including a microphone,determining an associated surface vector, the surface vector comprisinga vector perpendicular to the camera surface; identifying a subset ofthe surface vectors, the angular displacement between each identifiedsurface vector in the subset of surface vectors and the motion vectorcomprising an angle less than 90 degrees; and selecting the less thanall of the plurality of microphones based on the identified subset ofsurface vectors, the selected microphones located on camera surfacesassociated with surface vectors in the identified subset of surfacevectors.
 6. The method of claim 5, wherein the camera selects themicrophone associated with the surface vector with the smallest angulardisplacement from the motion vector.
 7. The method of claim 5, whereinthe camera selects the microphone associated with the surface vectorwith a largest angular displacement from the motion vector.
 8. Themethod of claim 1, wherein the motion vector is determined additionallybased on microphones associated with audio signals having abelow-threshold amount of wind noise.
 9. A camera, comprising: aplurality of microphones located on one or more surfaces of the camera,each configured to capture an audio signal; a processor configured to:identify one or more of the plurality of microphones based on thecaptured audio signals, each identified microphone associated with anaudio signal having an above-threshold amount of wind noise; determine amotion vector for the camera based on the identified microphones; andselect less than all of the plurality of microphones to activate basedon the motion vector; and a microphone controller configured to activateonly the selected microphones for capturing audio data and not theunselected microphones in the plurality of microphones such that theunselected microphones do not produce audio signals.
 10. The camera ofclaim 9, wherein the identified one or more microphones comprisemicrophones on adjacent surfaces of the camera.
 11. The camera of claim9, wherein the motion vector is determined such that one or more camerasurfaces that do not include an identified microphone face thedetermined motion vector.
 12. The camera of claim 9, the processorfurther configured to: for each camera surface including an identifiedmicrophone, determine a vector normal to the camera surface; anddetermine the motion vector based at least in part on a combination ofthe determined normal vectors.
 13. The camera of claim 9, whereinselecting less than all of the plurality of microphones comprises: foreach camera surface including a microphone, determining an associatedsurface vector, the surface vector comprising a vector perpendicular tothe camera surface; identifying a subset of the surface vectors, theangular displacement between each identified surface vector in thesubset of surface vectors and the motion vector comprising an angle lessthan 90 degrees; and selecting the less than all of the plurality ofmicrophones based on the identified subset of surface vectors, theselected microphones located on camera surfaces associated with surfacevectors in the identified subset of surface vectors.
 14. The camera ofclaim 13, wherein the camera selects the microphone associated with thesurface vector with the smallest angular displacement from the motionvector.
 15. The camera of claim 13, wherein the camera selects themicrophone associated with the surface vector with a largest angulardisplacement from the motion vector.
 16. The camera of claim 9, whereinthe motion vector is determined additionally based on microphonesassociated with audio signals having a below-threshold amount of windnoise.
 17. A method for activating at least one of a plurality ofmicrophones configured within a camera, comprising; capturing, by eachof the plurality of microphones, an audio signal; identifying one ormore of the plurality of microphones based on the captured audiosignals, each identified microphone associated with an audio signalhaving an above-threshold amount of wind noise; selecting less than allof the plurality of microphones based on the identified microphones,wherein each selected microphone comprises a microphone associated withan audio signal having a below-threshold amount of wind noise; andcapturing audio data using only the selected microphones and not theunselected microphones in the plurality of microphones such that theunselected microphones do not produce audio signals.
 18. The method ofclaim 17, wherein the identified one or more microphones comprisemicrophones on adjacent surfaces of the camera.
 19. The method of claim17, wherein the selected microphones comprise all microphones associatedwith an audio signal having a below-threshold amount of window noise.20. The method of claim 17, further comprising deactivating theidentified microphones.